Deliver IPC messages together with SwapCompositorFrame

android_webview/java/src/org/chromium/android_webview/AwContents.java

Index: android_webview/java/src/org/chromium/android_webview/AwContents.java
diff --git a/android_webview/java/src/org/chromium/android_webview/AwContents.java b/android_webview/java/src/org/chromium/android_webview/AwContents.java
index f166d99d6d895eb3aeecda8da6cdf05eeed601cf..d1574e73f9b0f0b3bf5f9e3a09aae6ee18cb0df8 100644
--- a/android_webview/java/src/org/chromium/android_webview/AwContents.java
+++ b/android_webview/java/src/org/chromium/android_webview/AwContents.java
@@ -49,6 +49,7 @@ import org.chromium.content.browser.ContentViewStatics;
 import org.chromium.content.browser.LoadUrlParams;
 import org.chromium.content.browser.NavigationHistory;
 import org.chromium.content.browser.PageTransitionTypes;
+import org.chromium.content.browser.WebContentsObserverAndroid;
 import org.chromium.content.common.CleanupReference;
 import org.chromium.content_public.Referrer;
 import org.chromium.content_public.browser.GestureStateListener;
@@ -201,6 +202,7 @@ public class AwContents {
     // Bound method for suppling Picture instances to the AwContentsClient. Will be null if the
     // picture listener API has not yet been enabled, or if it is using invalidation-only mode.
     private Callable<Picture> mPictureListenerContentProvider;
+    private boolean mDoDraw;
 
     private boolean mContainerViewFocused;
     private boolean mWindowFocused;
@@ -549,6 +551,8 @@ public class AwContents {
         return contentViewCore;
     }
 
+    private WebContentsObserverAndroid mWebContentsObserver;
+
     /**
      * Common initialization routine for adopting a native AwContents instance into this
      * java instance.
@@ -579,6 +583,13 @@ public class AwContents {
                 new AwGestureStateListener(), mContentViewClient, mZoomControls);
         nativeSetJavaPeers(mNativeAwContents, this, mWebContentsDelegate, mContentsClientBridge,
                 mIoThreadClient, mInterceptNavigationDelegate);
+        mWebContentsObserver = new WebContentsObserverAndroid(mContentViewCore) {
+            @Override
+            public void didFirstVisuallyNonEmptyPaint(int pageId) {
+                mDoDraw = true;
+                mContainerView.invalidate();
+            }
+        };
         mContentsClient.installWebContentsObserver(mContentViewCore);
         mSettings.setWebContents(nativeWebContents);
         nativeSetDipScale(mNativeAwContents, (float) mDIPScale);
@@ -779,6 +790,9 @@ public class AwContents {
             canvas.drawColor(getEffectiveBackgroundColor());
         }
 
+        if (!mDoDraw)
+            canvas.drawColor(0x88aaaaaa, android.graphics.PorterDuff.Mode.XOR);
+
         if (mOverScrollGlow != null && mOverScrollGlow.drawEdgeGlows(canvas,
                 mScrollOffsetManager.computeMaximumHorizontalScrollOffset(),
                 mScrollOffsetManager.computeMaximumVerticalScrollOffset())) {
@@ -881,6 +895,8 @@ public class AwContents {
      * @param params Parameters for this load.
      */
     public void loadUrl(LoadUrlParams params) {
+        mDoDraw = false;
+
         if (params.getLoadUrlType() == LoadUrlParams.LOAD_TYPE_DATA &&
                 !params.isBaseUrlDataScheme()) {
             // This allows data URLs with a non-data base URL access to file:///android_asset/ and